Think your kid isn't the brightest crayon in the box? Don't worry – one look at your child's DNA may soon help scientists predict whether he or she will have learning difficulties at school, so that you can take timely measures to avoid any problems.

Apparently, it's all in the genes. Research by scientists from King’s College London has shown that a genetic score of some 20,000 DNA variants explains up to 10 percent of differences in educational achievements of 16-year-old students. The authors of the study stressed that DNA gives a far better prediction of a pupil’s achievement than gender or grit – a trait measuring determination for attaining challenging goals.

Researchers studied the influence of genetic variants on results from GCSEs – a system of exams in England, Wales and Northern Ireland – in maths and English in 5,825 unrelated individuals aged 7, 12 and 16.

They calculated a “polygenic score” for each person, based on 20,000 known DNA variants across different genes. It turned out that children with higher polygenic scores obtained better GCSE grades, such as A and B grades, while those with low scores received between B and C. On top of that, "65 percent of people in the higher polygenic group went on to do A-levels, whereas only 35 percent from the lower group did so."

"Polygenic scores could be used to give us information about whether a child may develop learning problems later on, and these details could guide additional support that is tailored to a child's individual needs," Professor Plomin said. "We believe personalized support of this nature could help to prevent later developmental difficulties," he noted.

Saskia Selzam, first author from the MRC Social, Genetic & Developmental Psychiatry (SGDP) Center at King’s College London, added: "Through polygenic scoring, we found that almost 10 percent of the differences between children's achievement is due to DNA alone.

"Ten percent is a long way from 100 percent but it is a lot better than we usually do in predicting behavior. For instance, when we think about differences between boys and girls in maths, gender explains around 1 percent of the variance. Another example is grit, which describes the perseverance of an individual, and only predicts around 5 percent of the variance in educational achievement."

Scientists said their findings show that "what makes students achieve differently in their educational achievement is strongly affected by DNA differences."